ALEX Fetal Medicine Foundation reference ranges for umbilical artery and middle cerebral artery pulsatility index and cerebroplacental ratio

Journal article


Ciobanu, A., Wright, A., Syngelaki, A., Wright, D., Akolekar, R. and Nicolaides, K.H. 2019. ALEX Fetal Medicine Foundation reference ranges for umbilical artery and middle cerebral artery pulsatility index and cerebroplacental ratio. Ultrasound in Obstetrics and Gynecology. 53 (4), pp. 465-472. https://doi.org/10.1002/uog.20157
AuthorsCiobanu, A., Wright, A., Syngelaki, A., Wright, D., Akolekar, R. and Nicolaides, K.H.
Abstract

Objective: To develop reference ranges with gestational age for the pulsatility index in the umbilical artery (UA-PI) and fetal middle cerebral artery (MCA-PI and the cerebroplacental ratio (MCA-PI / UA-PI) and examine the maternal characteristics and medical history that affect these measurements.

Patients and methods: This was a cross-sectional study of 72,417 pregnancies undergoing routine ultrasound examination at 20+0 to 22+6 weeks’ gestation (n=3,712), or at 31+0 to 33+6 weeks (n=29,035) or at 35+0 to 36+6 weeks (n=37,282) or at 41+0 to 41+6 weeks (n=2,388). For the purpose of this study we included data for only one of the second or third trimester visits. The inclusion criteria were singleton pregnancy, dating by fetal crown-rump length at 11+0 to 13+6 weeks’ gestation, livebirth of morphologically normal neonate and ultrasonographic measurements by sonographers that had received the Fetal Medicine Foundation Certificate of competence in Doppler ultrasound. Since the objectives of the study were to establish reference ranges, rather than normal ranges, and to examine factors from maternal characteristics and medical history that affect these measurements, we included all pregnancies having routine ultrasound examinations irrespective of whether the mothers had a pre-existing medical condition, such as diabetes mellitus, or a pregnancy complication, such as preeclampsia or suspected fetal growth restriction. Median and standard deviation (SD) models were fitted between UA-PI, MCA-PI and CPR and gestational age. Assessment of goodness of fit of the models was by inspection of quantile to quantile (q-q) plots of z-scores calculated via the mean and SD models. The distributions of MCA PI, UA PI and CPR z-scores were examined in relation to maternal characteristics and medical history.

Results: The relationship between the median and gestation age was linear for UA-PI and cubic for MCA-PI and CPR and the SD was log quadratic for all three. MCA-PI and CPR increased with gestational age from 20 weeks’ gestation to reach a peak at around 32 and 34 weeks’ respectively, and decreased thereafter, whereas UA-PI decreased linearly with gestation from 20 to 42 weeks. Compared to the general population, significant deviations in MoM values of UA-PI, MCA-PI and CPR were observed in subgroups of maternal age, BMI, racial origin, method of conception and parity.

Conclusion: The study established new reference ranges of UA-PI, MCA-PI and CPR with gestational age and reports maternal characteristics and medical history that affect these
measurements.

KeywordsFetal middle cerebral artery pulsatility index; Umbilical artery pulsatility index; Cerebroplacental ratio; Doppler ultrasound; Reference range
Year2019
JournalUltrasound in Obstetrics and Gynecology
Journal citation53 (4), pp. 465-472
PublisherWiley
ISSN1469-0705
Digital Object Identifier (DOI)https://doi.org/10.1002/uog.20157
Official URLhttp://doi.org/10.1002/uog.20157
Publication dates
Online13 Feb 2019
Publication process dates
Accepted16 Oct 2018
Deposited03 Jun 2020
Accepted author manuscript
Output statusPublished
References

1. Nicolaides KH, Soothill PW, Rodeck CH, Campbell S. Ultrasound guided sampling
of umbilical cord and placental blood to assess fetal wellbeing. Lancet 1986; 1:
1065–1067.
2. Soothill PW, Nicolaides KH, Campbell S. Prenatal asphyxia, hyperlacticaemia,
hypoglycaemia and erythroblastosis in growth retarded fetuses. BMJ 1987; 294:
1051–1053.
3. Nicolaides KH, Bilardo KM, Soothill PW, Campbell S. Absence of end diastolic
frequencies in the umbilical artery a sign of fetal hypoxia and acidosis. BMJ 1988;
297: 1026–1027.
4. Vyas S, Nicolaides KH, Bower S, Campbell S. Middle cerebral artery flow velocity
waveforms in fetal hypoxaemia. Br J Obstet Gynaecol 1990; 97: 797–803.
5. Bilardo CM, Nicolaides KH, Campbell S. Doppler measurements of fetal and
uteroplacental circulations: relationship with umbilical venous blood gases measured
at cordocentesis. Am J Obstet Gynecol 1990; 162: 115–120.
6. Bahado-Singh RO, Kovanci E, Jeffres A, Oz U, Deren O, Copel J, Mari G.
The Doppler cerebroplacental ratio and perinatal outcome in intrauterine growth
restriction. Am J Obstet Gynecol 1999; 180: 750–756.
7. Gramellini D, Folli MC, Raboni S, Vadora E, Merialdi A. Cerebral-umbilical
Doppler ratio as a predictor of adverse perinatal outcome. Obstet Gynecol 1992; 79:
416–420.
8. DeVore GR. The importance of the cerebroplacental ratio in the evaluation of fetal
well-being in SGA and AGA foetuses. Am J Obstet Gynecol 2015; 213: 5–15.
9. Prior T, Mullins E, Bennett P, Kumar S. Prediction of intrapartum fetal compromise
using the cerebroumbilical ratio: a prospective observational study. Am J Obstet
Gynecol 2013; 208: 124.e1–6.
10. Morales-Rosello J, Khalil A, Morlando M, Papageorghiou A, Bhide A,
Thilaganathan B. Fetal Doppler changes as a marker of failure to reach growth
potential at term. Ultrasound Obstet Gynecol 2014; 43: 303–310.
11. Khalil AA, Morales-Rosello J, Morlando M, Hannan H, Bhide A, Papageorghiou A,
Thilaganathan B. Is fetal cerebroplacental ratio an independent predictor of
intrapartum fetal compromise and neonatal unit admission? Am J Obstet Gynecol
2015; 213: 54.e1–10.
12. Khalil A, Morales-Rosello J, Khan N, Nath M, Agarwal P, Bhide A, Papageorghiou A,
Thilaganathan B. Is cerebroplacental ratio a marker of impaired fetal growth
velocity and adverse pregnancy outcome? Am J Obstet Gynecol 2017; 216: 606.
e1–10.
13. Bakalis S, Akolekar R, Gallo DM, Poon LC, Nicolaides KH. Umbilical and fetal
middle cerebral artery Doppler at 30–34 weeks’ gestation in the prediction of adverse
perinatal outcome. Ultrasound Obstet Gynecol 2015; 45: 409–420.
14. Akolekar R, Syngelaki A, Gallo DM, Poon LC, Nicolaides KH. Umbilical and fetal
middle cerebral artery Doppler at 35–37 weeks’ gestation in the prediction of adverse
perinatal outcome. Ultrasound Obstet Gynecol 2015; 46: 82–92.
15. Kagan KO, Wright D, Spencer K, Molina FS, Nicolaides KH. First-trimester screening
for trisomy 21 by free beta-human chorionic gonadotropin and pregnancy-associated
plasma protein-A: impact of maternal and pregnancy characteristics. Ultrasound
Obstet Gynecol 2008; 31: 493–502.
16. Robinson HP, Fleming JE: A critical evaluation of sonar crown rump length
measurements. Br J Obstet Gynaecol 1975; 82: 702–710.
17. Acharya G, Wilsgaard T, Berntsen GK, Maltau JM, Kiserud T. Reference ranges
for serial measurements of umbilical artery Doppler indices in the second half of
pregnancy. Am J Obstet Gynecol 2005; 192: 937–944.
18. Vyas S, Campbell S, Bower S, Nicolaides KH. Maternal abdominal pressure alters
fetal cerebral blood flow. Br J Obstet Gynaecol 1990; 97: 740–742.
19. R Development Core Team. R. A language and environment for statistical
computing. R Foundation for Statistical Computing, Vienna, Austria. 2011; ISBN
3-900 051-07-0. http://www.R-project.org/
20. Ebbing C, Rasmussen S, Kiserud T. Middle cerebral artery blood flow velocities
and pulsatility index and the cerebroplacental pulsatility ratio: longitudinal reference
ranges and terms for serial measurements. Ultrasound Obstet Gynecol 2007; 30:
287–296.
21. Parra-Cordero M, Lees C, Missfelder-Lobos H, Seed P, Harris C. Fetal arterial and
venous Doppler pulsatility index and time averaged velocity ranges. Prenat Diagn
2007; 27: 1251–1257.
22. Bahlmann F, Fittschen M, Reinhard I, Wellek S, Puhl A. Blood flow velocity
waveforms of the umbilical artery in a normal population: reference values from
18 weeks to 42 weeks of gestation. Ultraschall Med 2012; 33: E80–87.
23. Morales-Rosell´o J, Khalil A, Morlando M, Herv´as-Mar´ın D, Perales-Mar´ın A.Doppler reference values of the fetal vertebral and middle cerebral arteries, at19-41 weeks gestation. J Matern Fetal Neonatal Med 2015; 28: 338–343.
24. Akolekar R, Sarno L, Wright A, Wright D, Nicolaides KH. Fetal middle cerebral
artery and umbilical artery pulsatility index: effects of maternal characteristics and
medical history. Ultrasound Obstet Gynecol 2015; 45: 402–408.
25. Wright D, Syngelaki A, Akolekar R, Poon LC, Nicolaides KH. Competing risks
model in screening for preeclampsia by maternal characteristics and medical history.
Am J Obstet Gynecol 2015; 213: 62.e1–10.
26. Lesmes C, Gallo DM, Panaiotova J, Poon LC, Nicolaides KH. Prediction of
small-for-gestational-age neonates: screening by fetal biometry at 19– 24 weeks.
Ultrasound Obstet Gynecol 2015; 46: 198–207.
27. Bakalis S, Silva M, Akolekar R, Poon LC, Nicolaides KH. Prediction of
small-for-gestational-age neonates: screening by fetal biometry at 30– 34 weeks.
Ultrasound Obstet Gynecol 2015; 45: 551–558.
28. Fadigas C, Saiid Y, Gonzalez R, Poon LC, Nicolaides KH. Prediction of
small-for-gestational-age neonates: screening by fetal biometry at 35– 37 weeks.
Ultrasound Obstet Gynecol 2015; 45: 559–565.
29. Vali˜no N, Giunta G, Gallo DM, Akolekar R, Nicolaides KH. Biophysical andbiochemical markers at 30– 34 weeks’ gestation in the prediction of adverse perinataloutcome. Ultrasound Obstet Gynecol 2016; 47: 194–202.30. Vali˜no N, Giunta G, Gallo DM, Akolekar R, Nicolaides KH. Biophysical andbiochemical markers at 35– 37 weeks’ gestation in the prediction of adverse perinataloutcome. Ultrasound Obstet Gynecol 2016; 47: 203–209.

Permalink -

https://repository.canterbury.ac.uk/item/8v478/alex-fetal-medicine-foundation-reference-ranges-for-umbilical-artery-and-middle-cerebral-artery-pulsatility-index-and-cerebroplacental-ratio

Download files

  • 15
    total views
  • 1
    total downloads
  • 0
    views this month
  • 0
    downloads this month

Export as

Related outputs

Value of routine ultrasound examination at 35-37 weeks' gestation in diagnosis of fetal abnormalities
Ficara, A., Syngelaki, A., Hammami, A., Akolekar, R. and Nicolaides, K. H. 2020. Value of routine ultrasound examination at 35-37 weeks' gestation in diagnosis of fetal abnormalities. Ultrasound in Obstetrics and Gynecology. 55 (1), pp. 75-80. https://doi.org/10.1002/uog.20857
Value of routine ultrasound examination at 35-37 weeks' gestation in diagnosis of non-cephalic presentation
De Castro, H., Ciobanu, A., Formuso, C., Akolekar, R. and Nicolaides, K. H. 2020. Value of routine ultrasound examination at 35-37 weeks' gestation in diagnosis of non-cephalic presentation. Ultrasound in Obstetrics and Gynecology. 55 (2), pp. 248-256. https://doi.org/10.1002/uog.21902
Comparison of different methods of measuring angle of progression in prediction of labor outcome
Frick, A., Kostiv, V., Vojtassakova, D., Akolekar, R. and Nicolaides, K. H. 2020. Comparison of different methods of measuring angle of progression in prediction of labor outcome. Ultrasound in Obstetrics and Gynecology. 55 (3), pp. 391-400. https://doi.org/10.1002/uog.21913
Diagnosis of fetal defects in twin pregnancies at routine 11-13-week ultrasound examination
Syngelaki, A., Cimpoca, B., Litwinska, E., Akolekar, R. and Nicolaides, K. H. 2020. Diagnosis of fetal defects in twin pregnancies at routine 11-13-week ultrasound examination. Ultrasound in Obstetrics and Gynecology. 55 (4), pp. 474-481. https://doi.org/10.1002/uog.21938
Metformin use in obese mothers is associated with improved cardiovascular profile in the offspring
Panagiotopoulou, O., Syngelaki, A., Georgiopoulos, G., Simpson, J., Akolekar, R., Shehata, H., Nicolaides, K. H. and Charakida, M. 2020. Metformin use in obese mothers is associated with improved cardiovascular profile in the offspring. American Journal of Obstetrics and Gynecology. https://doi.org/10.1016/j.ajog.2020.01.054
ISUOG Consensus Statement on organization of routine and specialist obstetric ultrasound services in the context of COVID-19
Abu-Rustum, R. S., Akolekar, R., Sotiriadis, A., Salomon, L. J., Da Silva Costa, F., Wu, Q., Frusca, T., Bilardo, C. M., Prefumo, F. and Poon, L. C. 2020. ISUOG Consensus Statement on organization of routine and specialist obstetric ultrasound services in the context of COVID-19. Ultrasound in Obstetrics and Gynecology. https://doi.org/10.1002/uog.22029
Impaired placental perfusion and major fetal cardiac defects
Fantasia, I., Andrade, W., Syngelaki, A., Akolekar, R. and Nicolaides, K.H. 2019. Impaired placental perfusion and major fetal cardiac defects. Ultrasound in Obstetrics and Gynecology. 53 (1), pp. 68-72. https://doi.org/10.1002/uog.20149
Routine first-trimester screening for fetal trisomies in twin pregnancy: cell-free DNA test contingent on results from combined test
Galeva, S., Konstantinidou, L., Gil, M.M., Akolekar, R. and Nicolaides, K.H. 2019. Routine first-trimester screening for fetal trisomies in twin pregnancy: cell-free DNA test contingent on results from combined test. Ultrasound in Obstetrics and Gynecology. 53 (2), pp. 208-213. https://doi.org/10.1002/uog.20160
Prediction of adverse perinatal outcome by cerebroplacental ratio in women undergoing induction of labor
Fiolna, M., Kostiv, V., Anthoulakis, C., Akolekar, R. and Nicolaides, K.H. 2019. Prediction of adverse perinatal outcome by cerebroplacental ratio in women undergoing induction of labor. Ultrasound in Obstetrics and Gynecology. 53 (4), pp. 473-480. https://doi.org/10.1002/uog.20173
Prediction of small for gestational age neonates: screening by maternal factors, fetal biometry, and biomarkers at 35-37 weeks' gestation
Ciobanu, A., Rouvali, A., Syngelaki, A., Akolekar, R. and Nicolaides, K.H. 2019. Prediction of small for gestational age neonates: screening by maternal factors, fetal biometry, and biomarkers at 35-37 weeks' gestation. American Journal of Obstetrics & Gynecology. 220 (5), pp. 486.e1-486.e11. https://doi.org/10.1016/j.ajog.2019.01.227
Prediction of small-for-gestational-age neonates at 35-37 weeks' gestation: contribution of maternal factors and growth velocity between 20 and 36 weeks
Ciobanu, A., Formuso, C., Syngelaki, A., Akolekar, R. and Nicolaides, K.H. 2019. Prediction of small-for-gestational-age neonates at 35-37 weeks' gestation: contribution of maternal factors and growth velocity between 20 and 36 weeks. Ultrasound in Obstetrics and Gynecology. 53 (4), pp. 488-495. https://doi.org/10.1002/uog.20243
Routine assessment of cerebroplacental ratio at 35-37 weeks' gestation in the prediction of adverse perinatal outcome
Akolekar, R., Ciobanu, A., Zingler, E., Syngelaki, A. and Nicolaides, K.H. 2019. Routine assessment of cerebroplacental ratio at 35-37 weeks' gestation in the prediction of adverse perinatal outcome. American Journal of Obstetrics & Gynecology. 221 (1), pp. 65.e1-65.e18. https://doi.org/10.1016/j.ajog.2019.03.002
Routine ultrasound at 32 vs 36 weeks' gestation: prediction of small-for-gestational-age neonates
Ciobanu, A., Khan, N., Syngelaki, A., Akolekar, R. and Nicolaides, K. H. 2019. Routine ultrasound at 32 vs 36 weeks' gestation: prediction of small-for-gestational-age neonates. Ultrasound in Obstetrics and Gynecology. 53 (6), pp. 761-768. https://doi.org/10.1002/uog.20258
Prediction of small-for-gestational-age neonates at 35-37 weeks' gestation: contribution of maternal factors and growth velocity between 32 and 36 weeks
Ciobanu, A., Anthoulakis, C., Syngelaki, A., Akolekar, R. and Nicolaides, K.H. 2019. Prediction of small-for-gestational-age neonates at 35-37 weeks' gestation: contribution of maternal factors and growth velocity between 32 and 36 weeks. Ultrasound in Obstetrics and Gynecology. 53 (5), pp. 630-637. https://doi.org/10.1002/uog.20267
Maternal and neonatal complications of fetal macrosomia: cohort study
Beta, J., Khan, N., Fiolna, M., Khalil, A., Ramadan, G. and Akolekar, R. 2019. Maternal and neonatal complications of fetal macrosomia: cohort study. Ultrasound in Obstetrics and Gynecology. 54 (3), pp. 319-325. https://doi.org/10.1002/uog.20279
Maternal and neonatal complications of fetal macrosomia: systematic review and meta-analysis
Beta, J., Khan, N., Khalil, A., Fiolna, M., Ramadan, G. and Akolekar, R. 2019. Maternal and neonatal complications of fetal macrosomia: systematic review and meta-analysis. Ultrasound in Obstetrics and Gynecology. 54 (3), pp. 308-318. https://doi.org/10.1002/uog.20279
Procedure-related risk of miscarriage following chorionic villus sampling and amniocentesis
Beta, J., Zhang, W., Geris, S., Kostiv, V. and Akolekar, R. 2019. Procedure-related risk of miscarriage following chorionic villus sampling and amniocentesis. Ultrasound in Obstetrics and Gynecology. 54 (4), pp. 452-457. https://doi.org/10.1002/uog.20293
Biomarkers of impaired placentation at 35-37 weeks' gestation in the prediction of adverse perinatal outcome
Ciobanou, A., Jabak, S., De Castro, H., Frei, L., Akolekar, R. and Nicolaides, K. H. 2019. Biomarkers of impaired placentation at 35-37 weeks' gestation in the prediction of adverse perinatal outcome. Ultrasound in Obstetrics and Gynecology. 54 (1), pp. 79-86. https://doi.org/10.1002/uog.20346
Risk of miscarriage following amniocentesis or chorionic villus sampling: systematic review of literature and updated meta-analysis
Salomon, L. J., Sotiriadis, A., Wulff, C. B., Odibo, A. and Akolekar, R. 2019. Risk of miscarriage following amniocentesis or chorionic villus sampling: systematic review of literature and updated meta-analysis. Ultrasound in Obstetrics and Gynecology. 54 (4), pp. 442-451. https://doi.org/10.1002/uog.20353
Prediction of large-for-gestational-age neonate by routine third-trimester ultrasound
Khan, N., Ciobanu, A., Karampitsakos, T., Akolekar, R. and Nicolaides, K. H. 2019. Prediction of large-for-gestational-age neonate by routine third-trimester ultrasound. Ultrasound in Obstetrics and Gynecology. 54 (2), pp. 326-333. https://doi.org/10.1002/uog.20377
Two-stage approach for prediction of small-for-gestational-age neonate and adverse perinatal outcome by routine ultrasound examination at 35-37 weeks' gestation
Akolekar, R., Panaitescu, A. M., Ciobanu, A., Syngelaki, A. and Nicolaides, K. H. 2019. Two-stage approach for prediction of small-for-gestational-age neonate and adverse perinatal outcome by routine ultrasound examination at 35-37 weeks' gestation. Ultrasound in Obstetrics and Gynecology. 54, pp. 484-491. https://doi.org/10.1002/uog.20391
Prevention of stillbirths: impact of a two-stage screening for vasa previa
Zhang, W., Geris, S., Beta, J., Ramadan, G., Nicolaides, K. H. and Akolekar, R. 2019. Prevention of stillbirths: impact of a two-stage screening for vasa previa. Ultrasound in Obstetrics and Gynecology. 55 (5), pp. 605-612. https://doi.org/10.1002/uog.21953
Impact of prospective measurement of outflow tracts in the prediction of coarctation of the aorta
Vigneswaran, T. V., Zidere, V., Chivers, S., Charakida, M., Akolekar, R. and Simpson, J. M. 2019. Impact of prospective measurement of outflow tracts in the prediction of coarctation of the aorta. Ultrasound in Obstetrics and Gynecology. https://doi.org/10.1002/uog.21957
Diagnosis of major heart defects by routine first-trimester ultrasound examination: association with high nuchal translucency, tricuspid regurgitation and abnormal flow in the ductus venosus
Minnella, G. P., Crupano, F. M., Syngelaki, A., Zidere, V., Akolekar, R. and Nicolaides, K. H. 2019. Diagnosis of major heart defects by routine first-trimester ultrasound examination: association with high nuchal translucency, tricuspid regurgitation and abnormal flow in the ductus venosus. Ultrasound in Obstetrics and Gynecology. 55 (5), pp. 637-644. https://doi.org/10.1002/uog.21956
Screening for pre-eclampsia using sFlt-1/PlGF ratio cut-off of 38 at 30-37 weeks' gestation
Dragan, I., Georgiou, T., Prodan, N., Akolekar, R. and Nicolaides, K. H. 2017. Screening for pre-eclampsia using sFlt-1/PlGF ratio cut-off of 38 at 30-37 weeks' gestation. Ultrasound in Obstetrics and Gynecology. 49 (1), pp. 73-77. https://doi.org/10.1002/uog.17301
Uterine artery pulsatility index at 30-34 weeks' gestation in the prediction of adverse perinatal outcome
Valiño, N., Giunta, G., Gallo, D. M., Akolekar, R. and Nicolaides, K. H. 2016. Uterine artery pulsatility index at 30-34 weeks' gestation in the prediction of adverse perinatal outcome. Ultrasound in Obstetrics and Gynecology. 47 (3), pp. 308-315. https://doi.org/10.1002/uog.14898
Biophysical and biochemical markers at 30-34 weeks' gestation in the prediction of adverse perinatal outcome
Valiño, N., Giunta, G., Gallo, D. M., Akolekar, R. and Nicolaides, K. H. 2016. Biophysical and biochemical markers at 30-34 weeks' gestation in the prediction of adverse perinatal outcome. Ultrasound in Obstetrics and Gynecology. 47 (2), pp. 194-202. https://doi.org/10.1002/uog.14928
Screening for trisomies by cell-free DNA testing of maternal blood: consequences of a failed result
Revello, R., Sarno, L., Ispas, A., Akolekar, R. and Nicolaides, K. H. 2016. Screening for trisomies by cell-free DNA testing of maternal blood: consequences of a failed result. Ultrasound in Obstetrics and Gynecology. 47 (6), pp. 698-704. https://doi.org/10.1002/uog.15851
Metformin versus placebo in obese pregnant women without diabetes mellitus
Syngelaki, A., Nicolaides, K. H., Balani, J., Hyer, S., Akolekar, R., Kotecha, R., Pastides, A. and Shehata, H. 2016. Metformin versus placebo in obese pregnant women without diabetes mellitus. New England Journal of Medicine. 374, pp. 434-43. https://doi.org/10.1056/NEJMoa1509819
Prospective first-trimester screening for trisomies by cell-free DNA testing of maternal blood in twin pregnancy
Sarno, L., Revello, R., Hanson, E., Akolekar, R. and Nicolaides, K. H. 2016. Prospective first-trimester screening for trisomies by cell-free DNA testing of maternal blood in twin pregnancy. Ultrasound in Obstetrics and Gynecology. 47 (6), pp. 705-11. https://doi.org/10.1002/uog.15913
Prediction of stillbirth from biochemical and biophysical markers at 11-13 weeks
Mastrodima, S., Akolekar, R., Yerlikaya, G., Tzelepis, T. and Nicolaides, K. H. 2016. Prediction of stillbirth from biochemical and biophysical markers at 11-13 weeks. Ultrasound in Obstetrics and Gynecology. 48 (5), pp. 613-617. https://doi.org/10.1002/uog.17289
Prediction of stillbirth from maternal demographic and pregnancy characteristics
Yerlikaya, G., Akolekar, R., McPherson, K., Syngelaki, A. and Nicolaides, K. H. 2016. Prediction of stillbirth from maternal demographic and pregnancy characteristics. Ultrasound in Obstetrics and Gynecology. 48 (5), pp. 607-612. https://doi.org/10.1002/uog.17290
Endoscopic placental laser coagulation in dichorionic and monochorionic triplet pregnancies
Peeva, G., Chaveeva, P., Gil Guevara, E., Akolekar, R. and Nicolaides, K. H. 2016. Endoscopic placental laser coagulation in dichorionic and monochorionic triplet pregnancies. Fetal Diagnosis and Therapy. 40 (3), pp. 174-180. https://doi.org/10.1159/000443792
Prediction of stillbirth from maternal factors, fetal biometry and uterine artery Doppler at 19-24 weeks
Akolekar, R., Tokunaka, M., Ortega, N., Syngelaki, A. and Nicolaides, K. H. 2016. Prediction of stillbirth from maternal factors, fetal biometry and uterine artery Doppler at 19-24 weeks. Ultrasound in Obstetrics and Gynecology. 48 (5), pp. 624-630. https://doi.org/10.1002/uog.17295
Prediction of stillbirth from placental growth factor at 11-13 weeks
Akolekar, R., Machuca, M., Mendes, M., Paschos, V. and Nicolaides, K. H. 2016. Prediction of stillbirth from placental growth factor at 11-13 weeks. Ultrasound in Obstetrics and Gynecology. 48 (5), pp. 618-623. https://doi.org/10.1002/uog.17288
Prediction of stillbirth from placental growth factor at 19-24 weeks
Aupont J. E., Akolekar, R., Illian, A., Neonakis, S. and Nicolaides, K. H. 2016. Prediction of stillbirth from placental growth factor at 19-24 weeks. Ultrasound in Obstetrics and Gynecology. 48 (5), pp. 631-635. https://doi.org/10.1002/uog.17229
Biophysical and biochemical markers at 35-37 weeks' gestation in the prediction of adverse perinatal outcome
Valiño, N., Giunta, G., Gallo, D. M., Akolekar, R. and Nicolaides, K. H. 2015. Biophysical and biochemical markers at 35-37 weeks' gestation in the prediction of adverse perinatal outcome. Ultrasound in Obstetrics and Gynecology. 47 (2), pp. 203-209. https://doi.org/10.1002/uog.15663